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Wednesday, August 21, 2019

Python Qt5 : contextMenu example.

A context menu is a menu in a graphical user interface (GUI) that appears upon user interaction, such as a right-click mouse operation.
I create the default application and I use QMenu to create this context menu with New, Open and Quit.
from PyQt5 import QtGui
from PyQt5.QtWidgets import QApplication, QMainWindow, QMenu
import sys


class Window(QMainWindow):
    def __init__(self):
        super().__init__()
        self.title = "PyQt5 Context Menu"
        self.top = 100
        self.left = 100
        self.width = 640
        self.height = 480
        self.InitWindow()


    def InitWindow(self):
        self.setWindowIcon(QtGui.QIcon("icon.png"))
        self.setWindowTitle(self.title)
        self.setGeometry(self.left, self.top, self.width, self.height)
        self.show()

    def contextMenuEvent(self, event):
        contextMenu = QMenu(self)
        new_Act = contextMenu.addAction("New")
        open_Act = contextMenu.addAction("Open")
        quit_Act = contextMenu.addAction("Quit")
        action = contextMenu.exec_(self.mapToGlobal(event.pos()))
        if action == quit_Act:
            self.close()


App = QApplication(sys.argv)
window = Window()
sys.exit(App.exec())

Tuesday, August 20, 2019

Python Qt5 : the QTimer class.

I haven't written about PyQt5 in a while and today I decided to add a short tutorial on this python module.
The QTimer class is a high-level programming interface for timers and provides repetitive and single-shot timers.
I this example I call a method every second with these lines:
        self.timer = QTimer()
        self.timer.timeout.connect(self.handleTimer)
        self.timer.start(1000)
The timer is stop when the value check by handleTimer has value 100 else the ProgressBar increment the default value with 1.
The full source of code is this:
import sys
from PyQt5.QtCore import QTimer
from PyQt5.QtWidgets import QApplication, QMainWindow, QProgressBar
from PyQt5.QtCore import Qt

class QTimer_ProgressBar(QMainWindow):

    def __init__(self):
        super().__init__()

        self.pbar = QProgressBar(self)
        self.pbar.setGeometry(30, 70,400, 50)
        self.pbar.setValue(0)

        self.setWindowTitle("QTimer Progressbar")
        self.setGeometry(64,64,640,480)
        self.show()

        self.timer = QTimer()
        self.timer.timeout.connect(self.handleTimer)
        self.timer.start(1000)

    def handleTimer(self):
        value = self.pbar.value()
        if value < 100:
            value = value + 1
            self.pbar.setValue(value)
        else:
            self.timer.stop()


if __name__ == '__main__':
    app = QApplication(sys.argv)
    ex = QTimer_ProgressBar()
    sys.exit(app.exec_())
You can also use it like this:
def Qt():
    try:
        # Do things
    finally:
        QTimer.singleShot(5000, Qt)

Qt()

Wednesday, August 14, 2019

Python 3.7.3 : Using the flask - part 014.

Today I worked on YouTube search with flask and Google A.P.I. project.
The source code is simple to understand and you can test any A.P.I. from google using this way.
I created a new Google project with YouTube A.P.I. version 3 and with the A.P.I. key.
I use this key to connect with flask python module.
I used the isodate python module.
You can see the source code on my GitHub repo named flask_yt.
The result is this:

Friday, August 9, 2019

Python 3.7.3 : Using the flask - part 013.

Flask uses Jinga2 template engine.
The Jinga2 template engine uses the following delimiters for escaping from HTML.
We can use this:
  • {% ... %} for Statements
  • {{ ... }} for Expressions to print to the template output
  • {# ... #} for Comments not included in the template output
  • # ... ## for Line Statements
The documentation webpage comes with all information about how can be used.
I create a new HTML5 file named layout.html and I will use this like an example:
{% if current_user.is_authenticated %}
...
{% else %}
...
{% endif %}
This file can be add into another file like this:
{% extends "layout.html" %}
{% block content %}
...
{% endblock content %}
For example, my about.html webpage comes with this source code:
{% extends "layout.html" %}
{% block content %}
    

About Page

{% endblock content %}
The routes.py this webpage will have this call:
@app.route("/about")
def about():
    return render_template('about.html', title='About')
In this way, I will add more HTML5 files to the project.


Thursday, August 8, 2019

Python 3.7.3 : Using the flask - part 012.

The goal of this tutorial step is to understand how the project can use the new features and implementation of the project.
Because in the last tutorial I used the flask_mail python module, now I will add into my project structure.
One good issue is registration issue for users.
First, you need to see the full project and changes at my GitHub project.
I used the itsdangerous python module to use tokens.
Let's install this with the pip tool:
C:\Python373\Scripts>pip install itsdangerous
For registration is need to have login issues and we can use LoginManager, see the extensions.py
#use SQLAlchemy
from flask_sqlalchemy import SQLAlchemy
#use LoginManager
from flask_login import LoginManager
#create login_manager
login_manager = LoginManager()
#create db
db = SQLAlchemy()
Let's see the new User model, see the models.py:
#imports for user model
from datetime import datetime
from .extensions import db
from itsdangerous import TimedJSONWebSignatureSerializer as Serializer
from blue_test import login_manager
from flask_login import UserMixin

# import db from base folder, see dot
from .extensions import db 

#load the user by id
@login_manager.user_loader
def load_user(user_id):
    return User.query.get(int(user_id))

# create the Texts mode
class Texts(db.Model):
    # primary key 
    id = db.Column(db.Integer, primary_key=True)
    title = db.Column(db.String(50))
    txt_content = db.Column(db.String(1000))
    
# create the User model
'''
id = id key for user
username = name
email = user email
password = user password

'''
class User(db.Model, UserMixin):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(20), unique=True, nullable=False)
    email = db.Column(db.String(120), unique=True, nullable=False)
    password = db.Column(db.String(60), nullable=False)

    def get_reset_token(self, expires_sec=1800):
        s = Serializer(app.config['SECRET_KEY'], expires_sec)
        return s.dumps({'user_id': self.id}).decode('utf-8')

    @staticmethod
    def verify_reset_token(token):
        s = Serializer(app.config['SECRET_KEY'])
        try:
            user_id = s.loads(token)['user_id']
        except:
            return None
        return User.query.get(user_id)

    def __repr__(self):
        return f"User('{self.username}', '{self.email}')"
In the blue_test folder project I created the templates folder with two HTML5 files: home.html and register.html.
I created also the forms.py file and I update with my forms: RegistrationForm,RequestResetForm, ResetPasswordForm.
#import python for create forms 
from flask_wtf import FlaskForm
from wtforms import StringField, PasswordField, SubmitField
# import python for validate forms field
from wtforms.validators import DataRequired, Length, Email, EqualTo, ValidationError
#import python files project
from .extensions import db, login_manager

class RegistrationForm(FlaskForm):
    username = StringField('Username',
                           validators=[DataRequired(), Length(min=2, max=25)])
    email = StringField('Email',
                        validators=[DataRequired(), Email()])
    password = PasswordField('Password', validators=[DataRequired()])
    confirm_password = PasswordField('Confirm Password',
                                     validators=[DataRequired(), EqualTo('password')])
    submit = SubmitField('Sign Up')

    def validate_username(self, username):
        user = User.query.filter_by(username=username.data).first()
        if user:
            raise ValidationError('That username is taken.')

    def validate_email(self, email):
        user = User.query.filter_by(email=email.data).first()
        if user:
            raise ValidationError('That email is taken.')

class RequestResetForm(FlaskForm):
    email = StringField('Email',
                        validators=[DataRequired(), Email()])
    submit = SubmitField('Password Reset')

    def validate_email(self, email):
        #get user by email
        
        if user is None:
            raise ValidationError('There is no account with that email.')

class ResetPasswordForm(FlaskForm):
    password = PasswordField('Password', validators=[DataRequired()])
    confirm_password = PasswordField('Confirm Password',
                                     validators=[DataRequired(), EqualTo('password')])
    submit = SubmitField('Reset Password')
In the __init__.py file I add this:
#import python files project
from .extensions import db, login_manager
...
    login_manager.init_app(app)
The routers.py will have the new RegistrationForm:
@api.route("/register", methods=['GET', 'POST'])
def register():
    # check if the user is authenticated
    if current_user.is_authenticated:
        return redirect(url_for('home'))
    form = RegistrationForm()
    if form.validate_on_submit():
        flash('Your account has been created!, 'success')
        return redirect(url_for('login'))
    return render_template('register.html', title='Register', form=form)
Depending on your needs, we will send and redirect these forms to the HTML files.
Depending on your needs (users, page access, ...) we will be able to write the source code further.

Wednesday, August 7, 2019

Python 3.7.3 : Using the flask - part 011.

The tutorial for today is focused on the email issue.
I will start with the new python module for flask named flask_mail.
Let's install it:
C:\Python373>cd Scripts

C:\Python373\Scripts>pip3 install flask_mail
Collecting flask_mail
...
Installing collected packages: blinker, flask-mail
Successfully installed blinker-1.4 flask-mail-0.9.1
The next source code let show you how can use this python module.
from flask import Flask 
from flask_mail import Mail, Message

app = Flask(__name__)
app.config['DEBUG'] = True
app.config['TESTING'] = False
app.config['MAIL_SERVER'] = 'smtp...'
app.config['MAIL_PORT'] = 25
app.config['MAIL_USE_TLS'] = False
app.config['MAIL_USE_SSL'] = False
#app.config['MAIL_DEBUG'] = True # debug 
app.config['MAIL_USERNAME'] = None
app.config['MAIL_PASSWORD'] = None
# this will send with the name of another@mail.com
#app.config['MAIL_DEFALT_SENDER'] = ('Another mail', 'another@mail.com')
app.config['MAIL_DEFALT_SENDER'] = None
app.config['MAIL_MAX_EMAILS'] = None # limit the messages send
#app.config['MAIL_SUPRESS_SEND'] = False # testing
app.config['MAIL_ASCII_ATTACHMENTS'] = False

# send an email with the flask application
mail = Mail(app)

@app.route('/mail')
def mail():
    #msg = Message('Hey', sender='another@mail.com')
    #msg = Message('Hey', recipients=['catafest@yahoo.com', 'another@mail.com'])
    #msg.add_recipient = ('another@mail.com')
    msg = Message('Hey', recipients=['catafest@yahoo.com'])

    # you can use body or HTML, using both wills receive the HTML first
    #msg.body = 'This is a body text message!'
    msg.html = 'This is a body text message with HTML5 tags!'

    #add a file attachment to message 
    with app.open_resource('photo.jpg') as add_file_res:
         msg.attach('photo.jpg', 'image/jpeg', add_file_res.read())
    '''
    #create a template message 
    msg = Message(
    subject ='',
    recipients=[],
    body = '',
    html = '',
    sender = '',
    cc = [],
    bcc = [],
    attachments = [],
    reply_to = [],
    date = '',
    charset = [],
    extra_headers = {'':''},
    mail_options = [],
    rcpt_options = []
    )
    '''
    #send mail
    mail.send(msg)
    return 'Message sent!'

@app.route('/bulk')
def bulk():
    users = [{'name':'Me', 'email':'another@mail.com'}]
    # open an connection 
    with mail.connect() as con:
         for user in users:
             msg = Message('Bulk message!', recipients=[user['email']]
             msg.body = 'Body message!'
             con.send(msg)
'''
# another example 
@app.route('/bulk')
def bulk():
    users = [{'name':'Me', 'email':'another@mail.com'}]
    # open an connection 
    with mail.connect() as con:
         for user in users:
             msg = Message('Bulk message!', recipients=[user.email]
             msg.body = 'Body message!'
             con.send(msg)
'''
if __name__ == '__main__':
    app.run()
You can see you need to set the settings for your mail server and then use it into flaks application.
The source code is easy to understand if you follow the commented rows.
I add also put into comments alternative examples for the template message and the bulk function.
This is the first step into sending emails with flask.
We can have a complete implementation on the project but all depends on project structure.